Might be scab - if you had fruits this year, it would have been very noticeable on those though. As the leaves are about to fall anyway, unless you post a pic of the problem, or give more details as to when it started, if the fruit was affected, whether the bark on the trunk looks healthy or has any sunken areas, just rake up all fallen leaves, do not leave any on the ground to overwinter. If it is scab, you may need to treat, but without further info, can't say.